What is Cilia?
- Many types of cells in the human body have microscopic projections called cilia that extend outward like hair. Often ranging in length from a few micrometers to several millimeters, they are both longer and fewer in number than microvilli. Cilia can be found in the respiratory system, the reproductive system, and the brain, among many others.
- In most cases, cilia are used to propel some sort of fluid or particle along a surface. Cilia play an important role in clearing the respiratory tract of mucus and other debris, which is then expelled via coughing or swallowing. Cilia on the inner lining of the fallopian tubes aid in the transport of the egg from the ovary to the uterus during reproduction.
- Microtubules, which are protein tubes with hollow centers, form the structure of cilia. The plasma membrane wraps around each microtubule, securing the cilium to the cell’s outer surface. Several different proteins are found in cilia, including motor proteins that transfer energy to microtubules to make the cilium wobble and bend.
- There are two distinct kinds of cilia, known as primary cilia and motile cilia. Primary cilia are located on cells that sense their environment and signal to other cells, while motile cilia are found on cells that need to transfer fluid or particles. Retinal cells’ main cilia, for instance, play a role in light sensing and the onset of vision.
- Infections of the respiratory tract, infertility, and birth defects are only few of the many symptoms caused by cilia disorders (also known as ciliopathies). Kartagener syndrome, primary ciliary dyskinesia, and Bardet-Biedl syndrome are only a few of the better-known ciliopathies.
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What is Microvill?
- Microvilli (singular: microvillus) are small, fingerlike projections that extend from the surface of cells in many different tissues and organs. They are typically several micrometers in length, making them substantially shorter than cilia at several millimeters.
- Microvilli are specialized projections from the surface of cells that help with fluid and nutrient absorption and secretion. Microvilli are found in high numbers in the small intestine, where they facilitate the digestion of food and the absorption of nutrients. Microvilli’s brushlike structure on the intestinal epithelium greatly expands the region of the epithelium that can absorb nutrients.
- Actin filaments are the building blocks of microvilli, and they are anchored to the cell membrane. They also contain proteins that aid in the transit of molecules across the cell membrane, such as transporters, channels, and enzymes. Microvilli are active, rapidly renewing structures that can rapidly recover from damage or loss.
- The effects of microvilli disorders are far-reaching. Celiac disease is an example of an autoimmune disorder; in this condition, the immune system mistakenly assaults the microvilli in the small intestine, resulting in nutrient loss and other issues. Microvilli in the respiratory and gastrointestinal tracts are vulnerable to damage from some viruses and bacteria, which can exacerbate respiratory and gastrointestinal symptoms.
Difference between Cilia and Microvilli
|Epithelial cells generate cilia, which are elongated, hair-like structures.||Microvilli are epithelial cell-derived membrane protuberances.|
|Cilia develop from basal granules.||Basal granules are lacking in microvilli.|
|Cylindrical cilia with tapered ends.||Microvilli are cylindrical and terminate in blunt tips.|
|Microvilli are shorter than cilia.||Cilia are longer than microvilli.|
|Microvilli are thinner than cilia.||Cilia are thinner than microvilli.|
|The glycocalyx does NOT coat the cilia.||Microvilli are typically coated with glycocalyx.|
|Cilia are motile and move back and forth to drive fluid in a particular direction.||Microvilli are not motile.|
|Cilia demonstrate a 9 + 2 configuration in their ultrastructure.||Microvilli do not have 9 + 2 configuration.|
|On the cell lining of the trachea and big bronchi are cilia.||On the cells lining the small intestine |
|Cilia have no function in absorption.||Microvilli enhance absorption.|
|Cilia do not increase the cell surface area on |
which they are present.
|Microvilli augment the cell’s surface |
area when they are present.